Abstract
The propargyl radical has twelve fundamental vibrational modes, r vib(HCCCH 2) = 5a 1 ⊕ 3b 1 ⊕ 4b 2, and nine have been detected in a cryogenic matrix. Ab initio coupled-cluster anharmonic force field calculations were used to help guide some of the assignments. The experimental HC=C-CH 2 matrix frequencies (cm -1) and polarizations are a 1 modes-3308.5 ±0.5, 3028.3 ±0.6, 1935.4 ±0.4, 1440.4 ±0.5, 1061.6 ±0.8; b 1 modes-686.6 ±0.4, 483.6 ±0.5; b 2 modes-1016.7 ±0.4, 620 ±2. We recommend a complete set of gas-phase vibrational frequencies for the propargyl radical, HC=C-CH 2 X̃ 2B 1. From an analysis of the vibrational spectra, the small electric dipole moment, μd(HCCCH 2) = 0.150 D, and the large resonance energy (HCCCH 2), roughly 11 kcal mol -1, we conclude that propargyl is a completely delocalized hydrocarbon radical and is best written as HC=C-CH 2.
Original language | American English |
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Pages (from-to) | 3812-3821 |
Number of pages | 10 |
Journal | Journal of Physical Chemistry A |
Volume | 109 |
Issue number | 17 |
DOIs | |
State | Published - 5 May 2005 |
NREL Publication Number
- NREL/JA-510-38403